CVE-2026-54464

Description

### Impact If this library is used in tandem with the `permessage-deflate` extension, a WebSocket server or client can be made to accept messages that are larger than the configured maximum message size. This is because this limit is checked against the message frames' length headers, which give the size of the compressed data, not the size after decompression. This can lead to applications accepting larger messages than expected and exceeding their intended resource usage. ### Patches The issue has been patched in version 0.8.1, by checking the length of messages after they are processed by incoming extensions. All users should upgrade to this version. ### Workarounds No known workarounds exist. ### Acknowledgements This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

How to fix CVE-2026-54464

To remediate CVE-2026-54464, upgrade the affected package to a fixed version below.

• —upgrade to 0.8.1 or later

Is CVE-2026-54464 being exploited?

No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-54464.

Affected packages (1)

• from 0, < 0.8.1

CVSS scores

References (5)

• PATCHgithub.com/faye/websocket-driver-ruby
• WEBgithub.com/faye/websocket-driver-ruby/releases/tag/0.8.1
• WEBgithub.com/faye/websocket-driver-ruby/security/advisories/GHSA-33ph-fccm-39pj
• WEBgithub.com/rubysec/ruby-advisory-db/blob/master/gems/websocket-driver/CVE-2026-54464.yml